Problem with my car. need help

[speedaddictM3]

For the last couple of days or so i noticed the car running a bit rough at idle especially when cold. Rpm would fluctuate a bit between 500 and 700. As if the engine was about to stall but doesnt. But yesterday twice and today also twice the car went into limp mode with reduced engine power and reduced redline. It happened when the car was either idling or when im off throttle and coming to a stop while in high gear such that rpm drops to just above idle level. I used a generic obd 2 scanner and it gave me a code for engine misfire and 4 codes for engine misfire in cylinders 5 6 7 and 8 which are all on engine bank 2, the drivers side. Today it also gave me a p0106 code for manifold absolute pressure sensor range error. And i had it scanned by an indy shop for bmw specific codes and they found code 2738 which said charge plausibility, diagnosis, cold start strategy, bank 2. That happens to be the same bank giving off the misfire codes. And if i shut down and restart the engine it runs fine and the limp mode goes away.

What could that be? My car is out of warranty and i dont want to go to the dealer unless necessary

[speedaddictM3]

Anything?

[a.wang]

Probably... ICV Bank 2 failure

[speedaddictM3]

Originally Posted by awong

Probably... ICV Bank 2 failure

But AFAIK there is only one idle control valve. Why would its failure affect one side of the engine only?

[a.wang]

There are two, one for each bank. That may not be your only problem though, just the most common one. Get that replaced first and see if that clears up anything. Plugs might need replacement too

[speedaddictM3]

Originally Posted by awong

There are two, one for each bank. That may not be your only problem though, just the most common one. Get that replaced first and see if that clears up anything. Plugs might need replacement too

I replaced all the plugs just a few months ago. Also are you confusing the throttle actuators with the idle control valve? There is only one idle valve for both banks. It is the one labelled #1 in this pic:

[a.wang]

Ahhh confusing the two names, my mistake! Yeah the actuators. My bank 2 one was just replaced as well as coolant temp sensor which was giving me wonky idles.